Collaboration is a fundamental and increasingly common feature in scientific research. Collaborative research has been associated with higher productivity, with higher impact, and, ultimately, with higher quality: from an economic perspective, collaboration allows the division of labor leading to reduced costs and time saving, facilitate access to scientific funding, to expensive (possibly large-scale) equipment, and to unique scientific data. From a bibliometric perspective, collaborative works are generally more visible and more cited by other scholars; moreover, they are rated higher by peer reviewers with respect to papers written in isolation, although notable exceptions exist.